Apparatus for treating wells



y L. c. CHAMBERLAIN ETAL 2,289,755 APPARATUS FOR TREA'I'i NG WELLS Filed Aug. 28, 1940 y IN VEN TOR EONARD C.CHAMBER Y ORMOND E. BARST s Y E N R O T A Patented July 14, 1942 Arr-snares 'Foa rnuarma warms Leonard C. Chamberlain and Ormofld E. Barstow, Midland,,Mich., assignors to The Dow Chemical Company, Midland, Mich, a corporation oi.

Michigan Application August 28, 1940, Serial No. 354,507

3 Claims. (9!. 166-1) The invention relates to a apparatus for treatf ing wells, such as oil, gas, brine and water wells,

whereby a fluid treating agent may be simultaneously introduced into at least two zones, while one zone is sealed from the other zone in such a manner that the, fluid in the well bore about to enter one zone is maintained out of contact with the fluid entering the other zone. It more par setting forth in detail a mode of carrying out the invention, such mode illustrating, however, but one of the various ways in which the invention may be put into operation.

In the accompanying drawing the single figure is a iragmentary view-partly in vertical cross section of a well bore showing an embodimentof ticularly concerns a method of treating wells whereby the fluid treating agent being simultaneously introduced into at least two zones may be controlled in such a manner that the rate flow to each zone may be varied at will during the course of a treatment.

The bore of a well oftentimes penetrates more than one zone, and it is usually desirable when treating such wells with a fluid treating agent, such as, for example, an acid, to control the rate atwhich the treating agent is entering each zone during the course of the treatment. For example, it is desirable to vary the rate of flow of acid being directed to each zone during the course of a treatment, because one zone may be some highly porous during the course or the treatment and absorb practically all of the treating agent with the result that waste of the treating fluid occurs and the most desirable results as regards the most effective increase in permeability are not obtained, It is further desirable when treating such wells that the introductionof' fluid agent into each zone or stratum takes place simultaneously, in order to avoid the necesslty of carrying. out a separate treatment of each zone.

The term zonefused herein and in the ap-' the invention.

As shown the well bore is lined with iron or steel pipe I down to a point 2 where it'is cemented in place by means of ce ent 3 The lower .portion of the well bore pene rates a productive stratum 4, an impervious stratum 5, and ends in a second productive stratum 6. The conventional well tubing 1 is shown extending into the well and is attached at its lower end to conduit 8 by means of a conventional coupling or collar 9. The conduit 8 is internally and externallythreaded at its lower end.- The externally threaded portion engages a second conduit Id, while a guide shoe H engages the internally threaded end. The second conduit I0 is provided with slotted port l2 and is also externally and internally threaded at its lower end in a manner similar to that of conduit 8. A tubular member l3 engages the lower end of conduit l0 externally thereof, while a second guide shoe ll identical with the upper guide shoe threadedly engages the lower end of conduit iii interiorly thereof. Tubular member i3 is attached at its lower end to conduit it by means of coupling 9. The conduit it supports packer it of conventional design shown seated against impervious stratum 5. Below the packing elepended claims, refers to separately defined strata,

a as well as portions or sections of the same formation or stratum.

It is, therefore, the principal object or the invention to provide a; method and apparatus whereby a fluid treating agent may be simultaneously introduced into at least two strata or zones penetratedby the bore of a well and at' the same time to'provide a means whereby the rate of flow of fluid may be varied during the.

course or the treatment so that the fluid may be caused to enter a selected zone at a more rapid or a slower rate.

Still other objects and advantages will be apparent as the description of the invention proceeds. a

The invention then resides in the method and apparatus hereinafter more. fully described and particularly pointed out in the claims, the following descriptlon and accompanying drawing ment it, the conduit it extends into the well and is provided with a port it through which fluid Y flows from the interior of the conduit M. f The lower end oi conduit it is shown sealed off by capmember H, which. is seated against the bottom of the well here. The guide shoes ll engaging the lower ends of conduits t and Ill are provided with centrally disposed openings 98 which flare out at theupper ends to provide a beveled surface IS. The lower ends of guide shoes II are provided with threaded shoulder portions 20.

Cap members 2| with centrally disposed openings engage the shoulders 20 and hold packing 22 against the shoulders 20. Thebeveledsurface IS on guide shoes it allows the conduit 23 to readily engage the centrally disposed openings in guide shoes ll while the paoking'gland formedat the lower end of the guide shoes allows conduit 23 to be raised and lowered in sliding sealing relationship through the guide-shoes. The conduit 231s provided with a series of spaced restricted ports 24 about its lower end, while at a point adjacent itslmperendrelatlvelylargeslottedportsfl throughtheguideshoesll.

The operation of the method will be best understood from the following description, wherein the apparatus illustrated is employed to carry out the simultaneous injection of acid into each of two productive strata 4 and 6. With the apparatus positioned as shown in the drawing, a quantity of acid is started into the well through tubing I. The acid flows downwardly and enters the slotted ports 25 provided in conduit 23. The acid then discharges through the ports 24 in conduit 23, a portion thereof being conflned to the space between the two guide shoes ll,while the remainder discharges into conduit I 4 and flows downwardly through packing element IE to the lower portion of the well. The acid discharging from the port 2 4 located between the guide shoes flows outwardly through port I! into the well bore adjacent productive stratum I, while the acid flowing downwardly through the packer discharges through port I into the wellbore adjacent productive stratum 8. As the treatment continues. a quantity of oil or the like may be introduced into the annular space between the tubing and the casing to control the level to which the acid may rise in the well bore. At any time during the treatment when it is desired to change the rate of flow of acid reagent to one stratum, it is onlyv necessary to raise or lower the wire line 2!, thus allowing more or less'of the restricted openings in conduit 23 to communi- 4o cate with the desired stratum. In this manner,

the ratio of rates of flow can be varied widely during the course of the treatment.

In the case of an acid treatment, it is usually desirable to inject a larger portion of the acid into the zone having the highest resistance to the flow offluids. By raising and lowering conduit 23 so as to expose most of the restricted .ports 25 to first one zone and then the other, the section requiring the application of the highest pressure to force fluid thereinto at a given rate is readily determined at anytime during The conduit 23 may then be the treatment.

positioned so as to direct a larger portion of the gig to the zone having the highest resistance The method will be found to have most general use in connection with an acid treatment wherein a solution of hydrochloric or other acid is introduced into the formation to bring about solution of the earth or rock formation and thus an'increase in size ofvthe new channels through which the desired mineral fluid flows to the well. In such treatments it will usually be found preferable to employ an aqueous solution of hydrochloric acid of from 5 to 25 per cent concentration. ,If desired, such an acid'may be inhibited against corrosive attack upon iron or steel in the manner taught in U. S. Patent Ila-1,877,504.

' "Although the. method has been described with particular reference to an acid treahnent, it is to be understood that any fluid treating agent may beintroduced in accordance with the method of the invention, Examples of such treating agents are paraflin solvents, liquid sealing agents,

and the like. 7 1 y In the above manner, a fluid treating agent may be simultaneously introduced into two or more strata or zones of production and at the same time the rate of flow of fluid to each zone is susceptible of control at all times during the treatment.

10 We claim:

1. In a well treating device for the simultaneous injection of a; fluid agent into at least two zones penetrated by the bore of a well, the combination which includes a conduit having spaced l5 openings therein, sealing means surrounding said conduitat a point between the openings adapted to seal the annular space ,between the conduit and the well bore, a tubular element disposed within the conduit having a relatively large fluid entry port adjacent the upper end and restricted fluid discharge ports adjacent the lower end, and means associated with the tubular element adapted to allow said element to be raised and lowered in the conduit, sealing means in the conduit surrounding the tubular element at points both above and below the upper spaced opening in the conduit, said sealing means being adapted to seal theannular space between the conduit ,and the tubular element ,and to allow the latter to be raised and lowered in sliding sealing relationship.

2. In a well treating device for the simultaneous injection of a fluid agent into at least two zones penetrated by the bore of a well, the

combination which includes a conduit having spaced openings therein, sealing means surrounding said conduit at a point between the open- Y ings adapted to seal the annular space between ,the conduit and the well bore, a weighted wire ,l line operated tubular element disposed in the conduit and having a relatively large fluid entry port adjacent the upper end and restricted fluid discharge ports adjacent the lower end, and seala ing means in the conduit surroundingthe wire .45 line "-operated tubular element at points both aboye and below the upper spaced opening in the conduit. said sealing means being' adapted to seal the annular space between the conduit and the wire line operated tubular element and .uof-m allow the latter to be raised and lowered in fsliding sealing relationship.

' 3. In a well treating device for the simultaneous injectioniof, a fluid agent into at least two zones penetrated by the bore of a well, the

combination whiclrincludes a conduit having spaced openings therein, sealing means surround-' ing said conduit at a point between the openings adapted to'seal theannular space between the conduit and the well bore, a tubular elementon disposed in said conduit having a relatively large fluid entry port adjacent the upper end thereof and restricted fluid discharge ports adjacent the lower end, sealing. means surrounding the tubular element at points both above and below the 05 upper opening in said conduit, said sealing means being adapted to seal the annular {space between the conduit and the tubular element and to allow the latterlto raise'dj'and lowered in sliding sealing relationship and a wire line at- 'tached to said tubular 'element forrai igg a d lowering said tubular elementim' LEONARDO. 0min ERLAIN ORMOND E. BARSTOW. 

